Add caching

service/main.go

@@ -1,9 +1,12 @@
 package main
 
 import (
+	"crypto/md5"
+	"encoding/hex"
 	"encoding/json"
 	"github.com/caarlos0/env/v6"
 	"log"
+	"meow.tf/go/cacheinterface"
 	"meow.tf/go/linkinfo"
 	"net"
 	"net/http"
@@ -12,10 +15,12 @@ import (
 )
 
 var (
-	api *linkinfo.LinkInfoApi
+	api            *linkinfo.LinkInfoApi
+	cacheInterface cache.CacheInterface
 )
 
 type apiConfig struct {
+	Cache                 string `env:"CACHE"`
 	LocalAddress          string `env:"LOCAL_ADDRESS"`
 	ImgurClientId         string `env:"IMGUR_CLIENT_ID"`
 	YoutubeKey            string `env:"YOUTUBE_KEY"`
@@ -57,9 +62,9 @@ func main() {
 
 	api = linkinfo.New(opts...)
 
-	if addr := os.Getenv("LOCAL_ADDRESS"); addr != "" {
-		var err error
+	var err error
 
+	if addr := os.Getenv("LOCAL_ADDRESS"); addr != "" {
 		api.Client, err = constructBoundClient(addr)
 
 		if err != nil {
@@ -67,6 +72,14 @@ func main() {
 		}
 	}
 
+	if config.Cache != "" {
+		cacheInterface, err = cache.New(config.Cache)
+
+		if err != nil {
+			log.Fatalln("Unable to create cache:", err)
+		}
+	}
+
 	mux := http.NewServeMux()
 	mux.HandleFunc("/info", handleInfoRequest)
 	http.ListenAndServe(":8080", mux)
@@ -82,6 +95,19 @@ func handleInfoRequest(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	h := md5.New()
+	key := hex.EncodeToString(h.Sum([]byte(urlStr)))
+
+	if cacheInterface != nil {
+		cached, err := cacheInterface.Get(key)
+
+		if cached != nil && err == nil {
+			w.Header().Set("Content-Type", "application/json")
+			w.Write(cached)
+			return
+		}
+	}
+
 	ret, err := api.Retrieve(urlStr)
 
 	if err != nil {
@@ -90,13 +116,19 @@ func handleInfoRequest(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Header().Set("Content-Type", "application/json")
-
-	err = json.NewEncoder(w).Encode(ret)
+	b, err := json.Marshal(ret)
 
 	if err != nil {
 		w.WriteHeader(http.StatusInternalServerError)
+		return
 	}
+
+	if cacheInterface != nil {
+		cacheInterface.Set(key, b, 10*time.Minute)
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.Write(b)
 }
 
 func constructBoundClient(addr string) (*http.Client, error) {